Dear OncoLink "Ask the Experts,"
My 12-year-old doberman has been diagnosed with both hemangiopericytoma and mast cell cancer. I find very little information on hemangiopericytoma. This tumor was incompletely removed from a hind leg. What is usual recommended treatment? Would 5-FU be beneficial in this type of cancer?
Lili Duda, VMD, Editor of the OncoLink Veterinary Oncology Section, responds:
Hemangiopericytomas fall into the category of "soft tissue sarcomas" or tumors that arise from the various connective tissues of the body. In general, these tumors can be very invasive locally, but are unlikely to metastasize (spread elsewhere in the body).
The treatment of choice is complete surgical removal. In locations where this is not possible (such as the head area and the limbs) surgery combined with radiation therapy is the treatment of choice. Systemic chemotherapy plays little role in the treatment of most of these tumors. However, "intralesional" chemotherapy (injecting chemotherapy drugs, such as 5-fluorouracil or cisplatin, directly into the tumor) has been advocated by some oncologists in cases where other definitive treatments are not an option (for example due to financial or travel constraints). While some individuals have reported good results, these results have not been published in the veterinary literature. So, while intralesional chemotherapy must be considered "experimental" at this time, it is a reasonable option to try if conventional therapy is not possible.
Each of the mentioned treatments has certain manageable risks, which must be weighed against potential benefits and your dog's overall health. These should be discussed with your veterinarian or veterinary oncologist, along with any other questions or concerns you may have.
If you or your veterinarian have not already done so, please consult a qualified veterinary oncologist to further explore the treatment options for your pet.